• Journal of the Korea Institute of Information and Communication Engineering
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• 제12권8호
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• pp.1434-1440
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• 2008

Performance of TCP/IP is studied on the wireless network using flow control and congestion control mechanism based on transmission rate. We discuss the elimination or the reduction of various phenomena of burst by flow controlling on transmission rate and verify that there are TCP ACK compression promblems on the queue by burst reaction while executing transmission rate controlled channels. Analyzing periodic burst reaction on the queue of source IP, the maximum value of queue is expected, which represents the applible expectation of throughput reduce and shows the improvement of performance by the reduce of throughput due to hi-directional traffic.

• Journal of Korean Elementary Science Education
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• 제38권2호
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• pp.244-262
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• 2019

The purpose of this study is to explore how the practical knowledge used by an elementary school science teacher during learner-centered science instruction can promote elementary students' construction of positive emotion. Using an auto-ethnographic approach over a period of three months, the researchers collected students' interest diaries, post interviews with students, video recordings in science classes, and students' personal diaries and analyzed them by means of the constant comparative method. In this way, the researchers categorized the structure of the practical knowledge held by the teacher and explained how it was applied in learner-centered science instruction to promote students' construction of positive emotion. Three images of an elementary science teacher's practical knowledge emerged and can be categorized under the following headings: 1) 'From science classroom to science $caf{\acute{e}}$', 2) 'Pleasant experiment class for all students and the teacher', and 3) 'A science class for students who were marginalized'. These images were backed up by principles and rules, and the teacher came to embody these images as he implemented these rules. This study also discusses how the impact of a science teacher's practical knowledge on students' construction of positive emotions can be interpreted as promoting positive outcomes rather than negative sanctions, meeting students' expectation from lab activities, and meeting the specific needs of marginalized students in a science class.

• Journal of Family Relations
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• 제21권3호
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• pp.95-122
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• 2016

Objectives: The purpose of this study was to find out the moderating effect of gender between parenting attitude and anger expression of adolescent. Particularly, to ensure that the anger of emotion is common nature, this study was conducted on the middle class adolescent of stable economic status. Method: The subjects of this study were 357 students, first grade from 3 high schools in Seoul. Data was analyzed by descriptive statistics, t-test, correlation, and hierarchial regression, using the SPSS 18.0 program. Results: The main results were as follows: First, in parenting attitude the perception of monitoring and affection was less important for boys than girls, but more important in over expectation and neglect. Second, in anger expression the level of anger-control appeared higher than anger-in and anger-out, no significant gender difference in subfactors. Third, the effect of gender moderated the relationships between parenting attitude and anger expression of adolescent. Conclusions: The results indicated the need to recognize gender difference in controlling anger of adolescent and to improve dysfunctional parenting attitude in middle class. Furthermore, the implications were discussed in enhancing parent-adolescent communication, developing emotional education programs, and preventing juvenile delinquency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권5호
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• pp.1630-1648
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• 2021

Owing to the unprecedented COVID-19 pandemic, the pharmaceutical industry has attracted considerable attention, spurred by the widespread expectation of vaccine development. In this study, we collect relevant topics from news articles related to COVID-19 and explore their links with two South Korean pharmaceutical indices, the Drug and Medicine index of the Korea Composite Stock Price Index (KOSPI) and the Korean Securities Dealers Automated Quotations (KOSDAQ) Pharmaceutical index. We use generalized Dirichlet-multinomial regression (g-DMR) to reveal the dynamic topic distributions over metadata of index values. The results of our analysis, obtained using g-DMR, reveal that a greater focus on specific news topics has a significant relationship with fluctuations in the indices. We also provide practical and theoretical implications based on this analysis.

• Asia Marketing Journal
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• 제18권3호
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• pp.47-63
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• 2016

Rational choice theory holds that the alternative with largest expected utility in the choice set should always be chosen. However, it is often observed that an alternative with the largest expected utility is not always chosen while the choice task itself being avoided. Such a choice phenomenon cannot be explained by the traditional expected utility maximization principle. The current study posits shows that such a phenomenon can be attributed to the gap between the expected perceived gain (or loss) and the expected perceived value. This study mathematically analyses the relationship between the expectation of an alternative's gains or losses over the reference point and its expected value, when the perceived gains or losses follow continuous probability distributions. The proposed expected value (EV) function can explain the effects of loss aversion and uncertainty on the evaluation of an alternative based on the prospect theory value function. The proposed function reveals why the expected gain of an alternative should exceed some positive threshold in order for the alternative to be chosen. The model also explains why none of the two equally or similarly attractive options is chosen when they are presented together, but either of them is chosen when presented alone. The EV function and EG-EV curve can extract and visualize the core tenets of the prospect theory more clearly than the value function itself.

• The Bulletin of The Korean Astronomical Society
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• 제46권1호
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• pp.27.3-27.3
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• 2021

Supernova (SN) cosmology is based on the assumption that the width-luminosity relation (WLR) in the type Ia SN luminosity standardization would not vary with progenitor age. Unlike this expectation, recent age datings of stellar populations in host galaxies have shown significant correlations between progenitor age and Hubble residual (HR). It was not clear, however, how this correlation arises from the SN luminosity standardization process, and how this would impact the cosmological result. Here we show that this correlation originates from a strong progenitor age dependence of the WLR and color-luminosity relation (CLR), in the sense that SNe from younger progenitors are fainter each at given light-curve parameters x1 and c. This is reminiscent of Baade's discovery of two Cepheid period-luminosity relations, and, as such, causes a serious systematic bias with redshift in SN cosmology. We illustrate that the differences between the high-z and low-z SNe in the WLR and CLR, and in HR after the standardization, are fully comparable to those between the correspondingly young and old SNe at intermediate redshift, indicating that the observed dimming of SNe with redshift is most likely an artifact of over-correction in the luminosity standardization. When this systematic bias with redshift is properly taken into account, there is no evidence left for an accelerating universe, and the SN data now support a decelerating cosmic expansion. Since the SN cosmology has long been considered as the most direct evidence for an accelerating universe with dark energy, this finding poses a serious question to one of the cornerstones of the concordance model.

• International conference on construction engineering and project management
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1209-1216
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• 2022

The majority of construction site incidents occur due to a lack of hazard awareness among workers on job sites. This lack of awareness is despite mandatory construction safety training, typically in the form of written content (safety manuals) or of images depicting hazards. To reduce job-site injuries and fatalities, general contractors have started adopting Virtual Reality (VR) to impart safety training to job site personnel. VR safety training can take the form of an immersive simulation comprising potential safety hazards intentionally embedded into a virtual job site; users are required to identify these hazards within a specified time frame with the expectation that they will be more adept at recognizing hazards on an actual job-site, resulting in fewer accidents. This research study seeks to identify the actual impacts of VR on construction safety awareness among participants. The research addresses the following question: Does VR improve hazard recognition awareness? The primary objective is to evaluate participants' performance of past construction safety awareness against present construction safety awareness after receiving VR training. Participants were asked to complete a multiple-choice Qualtrics™ questionnaire. The results of the study showed a statistically significant knowledge gain advantage with respect to hazard recognition and construction safety awareness with the use of interactive, immersive VR over a more conventional and passive safety training method.

• International conference on construction engineering and project management
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.503-507
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• 2015

Sustainability continues to gain traction in all industry sectors as people become aware of the advantages of green products. The voluntary use of green products in buildings in the United States continues to grow due to long-term cost saving and the ecological benefit to nature. The voluntary installation of green products is associated with end-users' expectations and perceptions including cost saving, sustainable behavior, and social responsibility. Although involuntary use of green products has similar expectations and perceptions, the installation decision is not based on the goodwill from end-users. This paper surveys college students to capture current experience levels, expectations, and perceptions in regard to green products and/or sustainability and to understand their attitudes about involuntary use of a green product. The installation of low water pressure showerheads in a dormitory provides data to support perception, expectation, and future direction of adoption of green products in public buildings. This information may be used to facilitate sustainable behaviors among involuntary groups regarding to the adoption of green products. The primary objective of this paper is to investigate the college students' perception of a green product, particularly when the students are involuntarily exposed to the green products. As a secondary objective, the paper also attempts to address the college students' general understanding on sustainability and green products. The findings of this study could support the growing importance of sustainable behavior among higher education beyond social responsibility and provide a benchmark against which to improve future change while fostering sustainable behaviors over time among the public.

• Journal of The Korean Association For Science Education
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• 제29권5호
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• pp.501-512
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• 2009

The purpose of this research is to compare the attitudes of female students in Korea toward science with the child-rearing attitude of their parents they perceived and their sex-role identity. The participants in this study were 374 female middle- and high-school students, chosen randomly from Seoul and Gyenggi-do in South Korea. We used three different forms of questionnaires in this research: "Scale of Parents' Child-rearing Behaviors Perceived by Teenagers", "Korea Sex-role Survey", and "Attitude Toward Science Measurement." The significant results were acquired after we had analyzed the comparison of the attitude of female students toward science with their perception on their parents' child-rearing attitude, especially on their fathers. The fathers' "monitoring" and "over-expectation" factors affected the attitudes of female students toward science; on the other hand, any child-rearing attitudes of their mothers did not influence their attitudes toward science. We also analyzed the attitudes of female students about science based on their sex-role identities. In consequence, we found that meaningful differences existed in four types of gender-role identity: androgyny type, masculinity type, femininity type and undifferentiated type. In particular, the androgyny type was characterized by a higher score in attitude toward science compared with the undifferentiated type.

• Journal of Korean society of Dental Hygiene
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• 제10권4호
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• pp.635-644
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• 2010

Objectives : The purpose of this study was to analyze and investigate the effecting factors on the actual condition of dental clinic use of the out patient. Methods : In oder to achieve this purpose, A survey for 302 patients in 6 participating dental clinics located in Daejeon metropolitan city from May 01 to May 30, 2010. The result of this study was as follows. Results : 1. The duration of dental clinic use was reflected in 36.1% of the under 1 year, 34.1% of over 2 years, and 29.8% of over 1 ~ under 2 years in order. Especially, the higher the duration of over 2 years the higher the age was, on married group had a significance. 2. The type of medical examination for samples was 27.6% of periodontal, 26.5% of conservative, 17.2% of prosthodontics, 10.9% of implant, and 7.9% of preventive in order. Especially, the male group the more the prosthodontics, implant had a significance. the higher the monthly income, on married group, the more the periodontal, prosthodontics and implant had a significance. 3. The motive of dental clinic selection was 38.4% of acquaintances' inducement, 33.4% of the superb treatment, 15.6% of easy convenience, and 7.0% of friendliness staff in order. Especially, male group the more the easy convenience, superb treatment, friendliness staff had a significance. 4. The mean of transportation in order to visit a dental clinic was 38.7% of public transportation, 37.5% of the own car, 23.8% of others in order. Especially, there was a highly significant difference on the public transportation in female, the lower education level, lower monthly income, and medical protection group. 5. The duration of time required of dental clinic reflected in 80.1% of the under 30 minute, 16.3% of over 30 minute~under 1 hour, and 3.6% of over 1 hour in order. Especially, the higher the treatment satisfaction, the dissatisfaction the higher the duration of time required under 30 minute had a significance. Conclusions : These results indicate that as medical services upgrade and get more varied, the expectation of medical quality also increases. It is thus considered that the revitalization of this hospital's management strategy can be achieved by providing highly developed medical services, and, more importantly, by better understanding the actual conditions of dental clinic use by the patients themselves.